U.S. patent number 5,525,242 [Application Number 08/325,062] was granted by the patent office on 1996-06-11 for apparatus and process for the aeration of water.
Invention is credited to Robert C. J. Kerecz.
United States Patent |
5,525,242 |
Kerecz |
June 11, 1996 |
Apparatus and process for the aeration of water
Abstract
This invention relates to improved apparatus and to an improved
process for the treatment of liquids, and particularly water for
domestic consumption. The improved process for treating water to
remove hydrogen sulfide and soluble mineral compounds while
saturating the water with oxygen comprises feeding the liquid
through a nozzle and contacting the liquid with an oxygen
containing gas, e.g., air comprises utilizing a venturi nozzle
having a nozzle extension that retains the water and air in the
form of a confined stream as it is discharged therefrom. The nozzle
extension preferably is equipped with restrictor means for
directing water from the interior walls of the nozzle chamber
toward the center and the nozzle extension directed so that the
stream of water containing air is directly discharged from the
nozzle extension into the water retained within the tank.
Inventors: |
Kerecz; Robert C. J. (Cape
Coral, FL) |
Family
ID: |
23266278 |
Appl.
No.: |
08/325,062 |
Filed: |
October 19, 1994 |
Current U.S.
Class: |
210/758; 210/220;
261/DIG.75; 48/189.5; 366/339; 261/79.2; 261/76 |
Current CPC
Class: |
C02F
1/72 (20130101); C02F 1/76 (20130101); B01F
3/04099 (20130101); C02F 3/1294 (20130101); B01F
5/0415 (20130101); B01F 5/0451 (20130101); C02F
1/20 (20130101); Y02W 10/15 (20150501); B01F
2003/04879 (20130101); Y02W 10/10 (20150501); Y10S
261/75 (20130101) |
Current International
Class: |
B01F
5/04 (20060101); C02F 1/20 (20060101); C02F
1/72 (20060101); C02F 1/76 (20060101); C02F
3/12 (20060101); B01F 3/04 (20060101); C02F
001/72 (); C02F 001/74 () |
Field of
Search: |
;261/DIG.75,76,79.2
;366/339 ;48/189.5 ;210/749,758,220 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McCarthy; Neil
Claims
What is claimed is:
1. In a process for the aeration of domestic water contaminated
with trace levels of dissolved gas and/or an oxidizable mineral
salt wherein said contaminated water is passed through a venturi
nozzle retained within a vessel, contacted with an oxygen
containing gas under conditions for oxidizing and/or removing said
gas and/or oxidizing said mineral salt, discharged from the venturi
nozzle and then the resultant aerated water collected within the
vessel, the improvement for improving the taste and removing
objectionable odor from the water which comprises:
utilizing a venturi nozzle having a nozzle chamber in which water
and oxygen containing gas are contacted, the contaminated water
passing through the venturi nozzle and discharging into the nozzle
chamber, said venturi nozzle having a nozzle extension in
communication with the nozzle chamber and venturi nozzle which
retains the water mixed with oxygen containing gas in the form of a
confined steam, discharging the confined stream therefrom and
venting gases from the vessel, said nozzle extension having a
restrictor therein, said restrictor located within said nozzle
extension, said restrictor comprising an annular element of
constant inner diameter that is smaller than a constant inner
diameter of the nozzle extension upstream from said restrictor, and
wherein said nozzle extension resumes downstream from said
restrictor at the same constant inner diameter of said nozzle
extension upstream from said restrictor.
2. The process of claim 1 wherein the venturi nozzle comprises a
tee having a water inlet that discharges into a nozzle chamber and
an inlet for oxidizing gas which discharges into said nozzle
chamber at an angle to said water inlet.
3. The process of claim 1 wherein the confined stream discharged
from the nozzle extension is directed toward the water retained in
the lower part of the vessel.
4. The process of claim 3 wherein the restrictor reduces the cross
sectional area of the nozzle extension by about 10 to 30% and said
restrictor is located proximate a discharge end of the nozzle
extension.
5. The process of claim 4 wherein the tee is substantially
cylindrical with nozzle extension having a spiral groove extending
along its length.
6. The process of claim 4 wherein the venturi nozzle has a tip
diameter of from about 3/16 to 1/2 inch.
7. The process of claim 6 wherein the diameter of said inlet for
oxidizing gas is from about 3/4 to 11/2 inches and the diameter of
the nozzle extension is from about 3/4 to 11/2 inches.
8. The process of claim 7 wherein the inlet for oxidizing gas is an
air inlet and is approximately 90.degree. to said water inlet.
9. The process of claim 8 wherein a halogen source is added to said
aerated water.
Description
FIELD OF THE INVENTION
This invention relates to a process and an apparatus for the
reduction and oxidation of dissolved gases and minerals in
water.
BACKGROUND OF THE INVENTION
Certain areas of the United States have serious water problems due
to the presence of dissolved gases and minerals. Hydrogen sulfide
is one of the gases often contained in these waters and its
presence renders domestic water unsuitable for consumption. Radon
is another gas often trapped in water in some sections of the
United States, and, if present in high concentrations, may be
dangerous. Objectionable amounts of soluble iron compounds and
soluble compounds of other metals such as manganese and strontium
may also be present in these waters. These dissolved gases and
minerals should be removed and/or oxidized in order to provide
water of domestic quality.
Small levels of organic components, e.g., hydrocarbons, organic
chlorides, etc., may also be present in domestic water. These
organic components must be removed, not only for consumption
purposes, but also in instances where environmental contamination
must be alleviated.
A variety of liquid treatment processes have been developed
involving the aeration of such liquids by contact with an oxygen
containing gas to remove the objectionable gases from the liquid as
well as oxidize any mineral salts to a relatively innocuous and
unobjectionable forms or convert such salts to precipitates which
may be filtered prior to use. Radon also has been effectively
removed from aqueous streams by aeration. Organic components have
been oxidized or stripped from the aqueous medium via aeration.
Representative prior art processes disclosing the treatment of
water via aeration for the purpose of providing domestic water free
of objectionable gases, mineral salts, radon and organic
contaminants are as follows:
U.S. Pat. No. 2,872,415 discloses a domestic water treatment
process for removing hydrogen sulfide and water soluble mineral
salts such as iron, manganese and strontium by contacting the water
with air. In principle, the water is first atomized at atmospheric
pressure via a spinning disk atomizer wherein it is violently mixed
with a controlled stream of air. This mixture then is impinged
against a barrier to enhance atomization and substantial oxidation
of the water as it passes through the unit. Complete gas
elimination is effected. The oxygen-saturated water is delivered to
a detention tank which is exposed to the atmosphere and held for a
short period of time, e.g., 20 to 60 minutes. Prior to use, the
water is filtered for delivery to the household.
U.S. Pat. No. 2,591,134 discloses an apparatus for the aeration of
liquids, and particularly water, suitable for the removal of
undesirable gaseous components such as hydrogen sulfide. The
apparatus consists of a shell having a water inlet and outlet and
means for controlling the level of water in the shell. Aeration is
effected by passing the water through a spray nozzle in
communication with an upwardly opening venturi tube for producing a
cone shaped spray of water. The spray is directed against a
horizontally disposed baffle plate having a depending edge flange
formed into a cone-shaped central part. Aeration of the water
stream is effected by introducing air from the outside via a duct
to the venturi tube. Violent mixing of the cone shaped spray of
water and air is effected by the impingement of the spray against
the horizontally disposed baffle plate. The resultant water mist
then falls downwardly and collects in the bottom of the shell
therein for subsequent use.
U.S. Pat. No. 2,495,937 discloses a water treatment process and
apparatus for the stabilization and sterilization of water. The
patent suggests that it has long been known to use softeners and
filters, as well as aeration, to remove gases which are in solution
in underground water, such gases including carbon dioxide, hydrogen
sulfide, methane, etc. The patent also disclosing a process for the
stabilization of treated water via chlorination, chlorination being
effected subsequent to aeration in order to minimize chlorine
losses to the atmosphere. The process involves withdrawing water
from a bottom portion of a large pool of water in an elevated
position, dividing the water stream into major and minor streams
and forcing both major and minor streams toward an upper portion of
the pool. Aeration is effected on the major stream and chemical
treatment is effected on the minor stream.
U.S. Pat. No. 2,590,431 discloses a water aerator and filter system
suited for removing objectionable gases such as carbon dioxide and
hydrogen sulfide therefrom. The aeration device consists of a tank
having agitation means therein, the agitation means having
apertures to enhance aeration of the water. Water level within the
tank is controlled by a flow control switch. Noxious vapors are
vented to the atmosphere.
U.S. Pat. No. 3,151,064 discloses a water conditioning method for
removing unpleasant odors and improving the taste via aeration.
Aeration is effected by means of horizontally disposed nozzles
having a plurality of small outlet passages oriented relative to
each other so that water and gases discharged therefrom impinge
against each other causing atomization of the water. The
intercepting water streams break up into individual water droplets
and assist the gas stream in dispersing the spray by creating a
high degree of turbulence. The water droplets fall into the tank
and are held for subsequent delivery to the user.
U.S. Pat. No. 4,869,832 discloses a radon removal system
incorporating a packed mass transfer aeration column sized to fit a
single story residential building. Air is blown upwardly through
the column and comes in contact with radon-laden water. On contact
the air forces the radon out of the water. The radon-laden air is
removed from the top of the column and vented to the atmosphere.
The treated water then is transferred to a storage tank for
subsequent use.
U.S. Pat. No. 2,088,691 discloses a gas liquid contacting apparatus
of a type similar to that previously described in U.S. Pat. No.
2,591,134. In operation, liquid is forced through a liquid jet at
high velocity through a chamber having a double cone or
venturi-like throat wherein it is caused to impinge against a
deflector having a cone shaped protrusion. The periphery of the
deflector has coaxially disposed serrated rings or skirts. Aeration
is effected by introducing air into the venturi-like chamber via
air inlets disposed below the liquid jet. The serrated rings are
suited for the purpose of further breaking up the liquid
stream.
SUMMARY OF THE INVENTION
This invention relates to an improved apparatus and to an improved
process for the treatment of liquids, and particularly water
rendering it suitable for domestic consumption.
Conventional aeration apparatus typically comprises a holding tank
or vessel for the treated water coupled with actuating means for
introducing water to the tank and effecting treatment thereof.
These tanks are equipped with level control means such that when
treated water is removed, additional water is introduced and
treated thus bringing the level of water back to its original
level. The water is contacted with air under conditions for
removing dissolved gases and oxidizing minerals. A venturi nozzle
connected to an air supply is often used to effect aeration of the
water. A basic process for treating liquid, and particularly, water
to remove hydrogen sulfide, methane, carbon dioxide, soluble
mineral compounds and/or small levels of organic contaminants, by
saturating the water with oxygen comprises feeding the water
through a nozzle and contacting the water with an oxygen containing
gas, e.g., air.
The improvement in the apparatus and process comprises resides
primarily in a venturi nozzle having a chamber in which water and
air are contacted and a nozzle extension that retains the water and
air in the form of a confined stream as it is discharged therefrom.
The nozzle extension preferably is equipped with restrictor means
for directing water from the interior walls of the nozzle chamber
toward the center and the nozzle extension directed so that the
stream of water containing air is directly discharged from the
nozzle extension into the water retained within the tank.
DRAWINGS
FIG. 1 is a vertical section in elevation taken through the water
aeration apparatus.
FIG. 2 is a sectional view in of the venturi aeration nozzle and
nozzle extension.
FIG. 3 is a view in elevation of the venturi halogenation
system.
FIG. 4 is a view in cross section of the nozzle chamber and
restrictor.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to the drawings to facilitate an understanding of
the invention. The invention comprising the apparatus and process
suited for use in effecting aeration of liquids thereby reducing
the level of dissolved gases therein and oxidizing soluble salts
and for producing water of high quality for household use is
described in further detail. Referring to FIG. 1, the apparatus
comprises a tank 2 which is vertically arranged for treatment of
water. These tanks for residential and small apartment usage range
in size from about 50 to 250 gallons with a fill time of 3 to 10
minutes although the tanks can be larger and flow rates adjusted
depending on the domestic requirements. The lower portion of tank 2
generally is adapted for holding the treated water while the upper
portion of tank 2 generally is adapted for aeration of the
contaminated water and removal of dissolved gas. Tank 2 is equipped
with an inlet 4 for introduction of contaminated water and an
outlet 6 for removal of treated water. A filter 7 may be introduced
into outlet 6 for purposes of removing particulate matter and
precipitated salts formed by the oxidation of minerals prior to
delivery to the end use application. The filter often is equipped
with a bypass of to permit sufficient flow to prevent damage to the
delivery pump should the filter become plugged. Optionally, outlet
6 may be used to drain tank 2 or tank 2 may be provided with a
separate drain. Tank 2 is closed to the elements by means of lid 8.
Lid 8 carries a vent 10 which is capable of permitting waste gases
to escape to the atmosphere. Typically, the vent is designed to
permit ingress and egress of air to the atmosphere but prevent
debris and insects from entering. Tank 2 also is equipped with an
air inlet 12 for supply of oxygen containing gas, e.g., air to a
venturi aeration system 14.
The key to aeration of the contaminated water is in venturi
aeration system 14. As is shown in FIG. 1, venturi aeration system
14 is supported in an upper section of tank 2, generally along the
side. It is supported in a generally vertical position with the
discharge from the venturi being directed toward the lower portion
of tank 2. Preferably the venturi aeration system is mounted above
the water level so that the discharge therefrom is into the treated
water. It can be directed so the discharge is upward or horizontal,
but preferred results are obtained when the discharge is directed
generally in a downward direction. Alternatively, the venturi may
be submerged with the discharge directed substantially downward or
horizontally, preferably downwardly. Optionally, a separate venturi
halogenating system 16 is provided within tank 2. It, too, is held
in a generally vertical position with the discharge thereof
preferably directed downwardly toward the lower portion of tank 2
and into the treated water.
As more clearly shown in FIG. 2, which is a view in cross section
of the venturi nozzle and nozzle extension, the venturi aeration
system 14 consists of a tee 30 having a venturi water inlet 32 at
an end of the tee which is adapted for communication with water
inlet 4 in tank 2 and a nozzle chamber 34. Tee 30 is tubular and
typically cylindrical in shape. Venturi water inlet 32 is disposed
within nozzle chamber 34 and narrows down to cone shaped nozzle 36.
Cone shaped nozzle 36 has reduced cross sectional area vis-a-vis
the venturi water inlet 32. By virtue of the reduced cross
sectional area or the nozzle, the velocity of the water as it is
passes through the nozzle and thus through the venturi aeration
system is caused to increase creating a venturi like effect. Unlike
cone shaped nozzles used heretofore for effecting aeration of the
water passing through, the stream discharged therefrom is focused
and confined rather than fan shaped, fan shaped resulting in
atomization of the stream. Air or other oxygen containing gas is
introduced through venturi air inlet 38 which is positioned at an
angle, generally positioned at a 90.degree. right angle, to venturi
water inlet 32 and is adapted for communication with air inlet 12
in tank 2. Air from outside tank 2 is pulled into nozzle chamber 34
by the venturi effect created by the passing of high velocity water
from cone shaped nozzle 36 into nozzle chamber 34. Air is caused to
pass from the discharge of venturi air inlet 38 across the
discharge end of cone shaped nozzle 36 and into nozzle chamber 34.
Venturi inlet chamber 38 is sized to inlet chamber 32 such that the
volume ratio of air vis-a-vis water passing through venturi
aeration section 14 is at least 1:1 and preferably at least 5:1.
For residential usage the diameter of the venturi water inlet
preferably will range from about 3/4 to 11/2 inches narrowing down
to a cone shaped nozzle diameter at the tip of about 3/16 to 1/2
inches. This ratio provides sufficient water velocity and capacity
so that a substantial volume of air will come into contact with the
water. For effective oxidation and/or stripping of dissolved gases
or organic components, a high air to water volume ratio is
required.
A nozzle extension 40 is disposed at the end of tee 30 which is in
axial alignment with venturi water inlet 32. Nozzle extension 40,
as shown, is of smaller diameter than that of the nozzle chamber
34. Although, nozzle extension 40 may be slightly narrower in
diameter and embrace the interior surface of tee 30. Nozzle
extension 40, as shown, generally extends from about 5 to 15 inches
below the discharge end of cone shaped nozzle 36. It has a length
such a portion of the water prior to discharge from cone shaped
nozzle 36 contacts the interior walls of the nozzle extension. Cone
shaped nozzle 34 may be modified to enhance such side wall or
interior wall contact by directing the water discharged therefrom
while maintaining a generally focused stream as is passes through
the nozzle extension. At a point generally near the discharge end
of nozzle extension 40, typically 1/2 to 11/2 inches from the
discharge end there is positioned a restrictor 42 which serves to
force the water as it passes through the nozzle extension 40 from
the interior walls or sides toward the center of the nozzle
extension. The restrictor 42 is located proximate a discharge end
of the nozzle extension 40. The restrictor 42 comprises an annular
element of constant innner diameter that is smaller than a constant
inner diameter of the nozzle extension 40 upstream from the
restrictor 42. The nozzle extension 40 resumes downstream from the
restrictor 42 at the same constant inner diameter of said nozzle
extension 40 upstream from the restrictor 42. A view in cross
section of the nozzle extension and restrictor is shown in FIG. 4.
In effect, restrictor 42 causes the water flowing down the walls to
hold up in the nozzle. The high velocity, focused water stream
exiting cone shaped nozzle 42, coupled with incoming air, impacts
the water held within nozzle extension 40 and causes substantial
mixing and substantial aeration thereof. Restrictor 42 is sized to
reduce the cross sectional area of nozzle extension 40 by about 10
to 30 percent. Optionally, nozzle extension 40 carries a spiral
groove 44 on its interior surface. Spiral groove 44 tends to cause
the water as it is discharged from cone shaped nozzle 36 to spiral
much like rifling in the barrel of a rifle. The spiral effect is
believed to add to the turbulence in nozzle extension 40,
particularly when the water is forced from the interior walls to
the center by restrictor 42 and in contact with the high velocity
stream from cone shaped nozzle 34. If nozzle restrictor 40 is not
present, and a small portion of water forced from the walls and
possibly held up within nozzle extension 40, air from the tank
which is contaminated with dissolved gases may contact the water.
But, more importantly, the volume of air pulled in via air inlet 38
by the venturi effect in venturi aeration system 14 is
substantially less. As a result there may be less oxidation of the
minerals and less removal of dissolved gases.
As is known the key to removing dissolved gases such as carbon
dioxide, methane, radon and hydrogen sulfide from contaminated
water lies in effecting substantial aeration of the water. The
venturi aeration system is extremely effective in achieving this
result. One feature is that the meeting of air with high velocity
water from cone shaped nozzle 36 causes substantial turbulence
within nozzle chamber 34. This turbulence causes enhanced mixing of
the air with the water. Nozzle extension 40 retains the mixture of
water and air under pressure for a slight period of time.
Obviously, that time is dependent upon the length of the nozzle.
But, nonetheless, that time serves to incorporate the air into the
water. In addition, if restrictor 42 is used in addition to the
extension provided by extended nozzle 40, further pressure and
higher velocity are imparted thereby creating turbulence and mixing
of air with the water in the confined space of the nozzle. Then, on
discharge, there is a release of pressure causing dissolved gas to
be flashed therefrom. Additionally, the rotation of the water as it
is discharged from extended nozzle 40 tends to focus the stream
into a narrow path causing it to strike the treated water with more
force causing greater turbulence and air retention in the treated
water retained in the lower portion of tank 2. By causing the
water-air mixture to be discharged into the treated water under
high velocity, the treated water is contacted with additional
oxygen containing gas which can bubble through the treated water
and remove any residuum of undesirable gases. That feature is
essentially lost if the discharge is directed away from the water
retained in the lower portion of tank 2.
Residual treatment of the aerated water to remove bacteria and
organic components is accomplished via treatment with a halogen,
e.g., chlorine or bromine. Preferably, chlorine is used as the
agent for treatment. Referring primarily to FIG. 3, halogenation is
accomplished by means of a venturi halogenation system 16. It
consists of a tee chamber 50 having two ends in axial alignment and
a leg in perpendicular alignment with the other legs. A conduit 52
which comprises a narrow tube 51 communicates with a halogen source
17. One of the axially aligned legs 52 is in communication with
venturi water inlet chamber 32 whereby a small portion of water
introduced via water inlet 4 is diverted through the axially
aligned leg of tee chamber 50. Water as it passes through the
venturi halogenation system 16 pulls a small amount of the halogen
treating agent through the perpendicularly aligned leg into tee
chamber 50 wherein it is then discharged from the other axially
aligned leg 54 to the treated water retained in the lower portion
of tank 2. The turbulence created in the treated water by venturi
aeration system 14 is sufficient to effect thorough mixing of the
halogen treating agent with the treated water. The venturi
halogenation system 16 is sized such that a small preselected
amount of halogen is introduced to the treated water in
conventional amounts.
The water treatment system may be made from conventional materials
of construction. Often tank 2 is made from reinforced polyester,
polypropylene, or high density polyethylene while the venturi
aeration system and venturi halogenation system are made from nylon
or other polymeric components. As with conventional treatment
systems, electrical control means 18 can be provided to maintain a
desired liquid level in the tank coupled with a moderate residence
time to permit escape of dissolved gases.
In contrast to many of the aeration systems developed heretofore,
the water as it is discharged from the venturi nozzle extension is
maintained within a narrow high velocity stream. Many or the
earlier venturi systems focused on atomizing the water as it was
discharged from the venturi nozzle.
* * * * *